Did you manually set the player to libVLC? If so, try setting it to exoplayer. I've had a much more consistent experience setting it to exoplayer on my CCwGTV 4K.
Jellyfin 10.10.3 (Docker)
Ubuntu 24.04 LTS
Intel i3 12100
Intel Arc A380
OS drive - SK Hynix P41 1TB
Storage
3x WD Red Pro 6TB CMR in RAIDZ1 (JF Library)